US6340402B1 - Filters - Google Patents
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- Publication number
- US6340402B1 US6340402B1 US09/232,563 US23256399A US6340402B1 US 6340402 B1 US6340402 B1 US 6340402B1 US 23256399 A US23256399 A US 23256399A US 6340402 B1 US6340402 B1 US 6340402B1
- Authority
- US
- United States
- Prior art keywords
- end cap
- gasket
- adhesive
- filter medium
- mesh tube
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
- 239000000853 adhesive Substances 0.000 claims abstract description 20
- 230000001070 adhesive effect Effects 0.000 claims abstract description 20
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 claims abstract description 14
- 229910052799 carbon Inorganic materials 0.000 claims abstract description 13
- 238000000034 method Methods 0.000 claims abstract description 8
- 230000002093 peripheral effect Effects 0.000 claims abstract description 8
- 230000015572 biosynthetic process Effects 0.000 claims abstract description 6
- 239000007769 metal material Substances 0.000 claims abstract description 4
- 230000009974 thixotropic effect Effects 0.000 claims abstract description 4
- 239000011324 bead Substances 0.000 claims description 3
- 239000013618 particulate matter Substances 0.000 claims 1
- 239000002184 metal Substances 0.000 description 4
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 description 3
- 239000002245 particle Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 241000273930 Brevoortia tyrannus Species 0.000 description 1
- 229920001410 Microfiber Polymers 0.000 description 1
- 239000003570 air Substances 0.000 description 1
- 239000012080 ambient air Substances 0.000 description 1
- 229920002678 cellulose Polymers 0.000 description 1
- 239000001913 cellulose Substances 0.000 description 1
- 238000005056 compaction Methods 0.000 description 1
- 230000006835 compression Effects 0.000 description 1
- 238000007906 compression Methods 0.000 description 1
- 239000004744 fabric Substances 0.000 description 1
- 238000001914 filtration Methods 0.000 description 1
- 239000011521 glass Substances 0.000 description 1
- 238000000227 grinding Methods 0.000 description 1
- 239000000314 lubricant Substances 0.000 description 1
- 239000000463 material Substances 0.000 description 1
- 239000003658 microfiber Substances 0.000 description 1
- 239000002674 ointment Substances 0.000 description 1
- 231100000614 poison Toxicity 0.000 description 1
- 229920001084 poly(chloroprene) Polymers 0.000 description 1
- 239000012858 resilient material Substances 0.000 description 1
- 238000007789 sealing Methods 0.000 description 1
- 239000003440 toxic substance Substances 0.000 description 1
Images
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/52—Particle separators, e.g. dust precipitators, using filters embodying folded corrugated or wound sheet material
- B01D46/521—Particle separators, e.g. dust precipitators, using filters embodying folded corrugated or wound sheet material using folded, pleated material
-
- A—HUMAN NECESSITIES
- A62—LIFE-SAVING; FIRE-FIGHTING
- A62B—DEVICES, APPARATUS OR METHODS FOR LIFE-SAVING
- A62B23/00—Filters for breathing-protection purposes
- A62B23/04—Filters for breathing-protection purposes for gasproof shelters
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/0084—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours provided with safety means
- B01D46/0091—Including arrangements for environmental or personal protection
- B01D46/0094—Including arrangements for environmental or personal protection against radiation
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D46/00—Filters or filtering processes specially modified for separating dispersed particles from gases or vapours
- B01D46/24—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies
- B01D46/2403—Particle separators, e.g. dust precipitators, using rigid hollow filter bodies characterised by the physical shape or structure of the filtering element
- B01D46/2411—Filter cartridges
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2253/00—Adsorbents used in seperation treatment of gases and vapours
- B01D2253/10—Inorganic adsorbents
- B01D2253/102—Carbon
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01D—SEPARATION
- B01D2265/00—Casings, housings or mounting for filters specially adapted for separating dispersed particles from gases or vapours
- B01D2265/04—Permanent measures for connecting different parts of the filter, e.g. welding, glueing or moulding
-
- Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
- Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
- Y10S55/00—Gas separation
- Y10S55/05—Methods of making filter
Definitions
- This invention relates to improvements in filters, and more particularly to improvements in so-called “Nuclear, Biological and Chemical” (NBC) Filters which comprise a tube of pleated filter material surrounded by particulate carbon in turn surrounded by a petal mesh. Ambient air drawn into the interior of the tube at one end is discharged through the mesh into an enclosure such as the interior of a ship, having undergone filtration to remove toxic substances.
- NBC Nuclear, Biological and Chemical
- a principal object of the present invention is to provide an improved filter and method of assembling the same.
- a method of assembly of a NBC Filter comprising a tubular formation of an inner filter medium closed at at least one end by a metallic inner end cap, a tubular mass of graulated carbon surrounding said inner filter medium to from an outer filter medium, a tubular mesh enclosing said outer filter medium, a annular, resilient gasket surrounding said inner end cap and an outer end cap of metallic material having a peripheral skirt which, in use, surrounds one end of the mesh tube while the gasket is compressed between the outer end cap and the carbon mass, the method comprising interposing a thixotropic adhesive between the inner periphery of the gasket and the inner end cap, between the outer periphery of the gasket and the mesh tube and between the gasket and the outer end cap.
- a continuous bead of said adhesive is applied to the gasket while the latter is in an unstressed condition and where the latter projects from the mesh tube before the outer end cap is brought to compress the gasket with its skirt surrounding and riveted to the mesh tube.
- the adhesive used is preferably MIL-A-46146B, Group II, Type 1, such as that known as “Loctite 5145”.
- the outer surface of the inner end cap and the inner surface of the outer end cap are first sand-blasted and then cleaned prior to contact with the adhesive.
- FIG. 1 which is an exploded sectional elevation of a NBC filter.
- the NBC filter 10 illustrated comprises a tubular formation 11 of pleated cellulose paper impregnated and/or coated with microfibre glass. This is surrounded in spaced relation by a perforated metal housing or mesh tube 12 backed by a fine fabric scrim (not shown). The annular space between the mesh 12 and inner filter medium 11 is filled with a loose mass of granulated carbon (not shown).
- a socket 13 permits the admission to the interior of the tube 11 of air rom outside the enclosure from, cabin or the like) being protected by the filter.
- a lower end cap 14 surrounds socket 13 and closes off the bottom end of the formation 11 and the lower end of the space between it and the housing 12 .
- a metallic, inner end cap is closes the top end of the formation 11 .
- An annular gasket 16 of resilient material such as Neoprene rubber, is located on the tubular mass of carbon granules so that in its unstressed condition it projects slightly fromthe tubes 11 and 12 .
- the gasket 16 is compressed when an outer end cap 17 of a metallic material is now brought down until its peripheral skirt 18 surrounds the upper end of the housing 12 . Rivets (not shown) may now be used to secure the skirt 18 of the outer end cap to the housing 12 .
- a continuous bead of a thixotropic adhesive is applied to a surface of the gasket 16 exposed from the carbon granules, for example a peripheral region of its upper surface as show so that when the outer end cap 17 is brought to compress the gasket there will be adhesive between the outer periphery 19 of the gasket and both the inner surface of the skirt 18 of the outer end cap and the outer surface of the metal mesh 12 .
- the adhesive used is preferably MIL-A-46146B, Group II, Type 1, such as that known as “Loctite 5145”.
- the adhesive will serve as a lubricant and it will fill any voids between the mesh the gasket and the outer end cap. After cure the adhesive will provide a seal against the escape of carbon powder but will retain sufficient resilience to allow the gasket to unction as in prior art filters.
Landscapes
- Chemical & Material Sciences (AREA)
- Health & Medical Sciences (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Toxicology (AREA)
- Physics & Mathematics (AREA)
- Environmental & Geological Engineering (AREA)
- Engineering & Computer Science (AREA)
- Geometry (AREA)
- General Health & Medical Sciences (AREA)
- Business, Economics & Management (AREA)
- Emergency Management (AREA)
- Filtering Materials (AREA)
- Filtering Of Dispersed Particles In Gases (AREA)
Abstract
A method of assembly of a NBC Filter comprising a tubular formation of an inner filter medium closed at lease one end by a metallic inner end cap, a tubular mass of granulated carbon surrounding said inner filter medium to form an outer filter medium, a tubular mesh enclosing said outer filter medium, an annular, resilient gasket surrounding said inner end cap and an outer end cap of metallic material having a peripheral skirt which, in use, surrounds one end of the mesh tube while the gasket is compressed between the outer end cap and the carbon mass. A thixotropic adhesive is interposed between the inner periphery of the gasket and the inner end cap, between the outer periphery of the gasket and mesh tube and between the gasket and the outer end cap.
Description
This invention relates to improvements in filters, and more particularly to improvements in so-called “Nuclear, Biological and Chemical” (NBC) Filters which comprise a tube of pleated filter material surrounded by particulate carbon in turn surrounded by a petal mesh. Ambient air drawn into the interior of the tube at one end is discharged through the mesh into an enclosure such as the interior of a ship, having undergone filtration to remove toxic substances. Such filters are used, for example in ships or bunkers, to protect the occupants in the event of nuclear, biological or chemical attack.
Although filters of this kind have been in use for about 30 years no satisfactory solution has hitherto been found to the problem that leakage of the particulate carbon can occur particularly at the junction of the tube of metal mesh with a metal end cap used to close it. The end cap is formed with a peripheral flange or skirt which surrounds said end of the mesh tube and may be riveted to it, but carbon particles may nevertheless escape. Conventionally a resilient gasket is pressed onto the carbon particles when the end cap is fitted, but rough handling of the filter e.g. during transport or testing may cause compaction and powdering of the carbon granules in turn leading to voids within the carbon mass which will reduce the sealing efficiency of the gasket, and subsequent failure of the filter.
A principal object of the present invention is to provide an improved filter and method of assembling the same.
In accordance with one aspect of the present invention there is provided a method of assembly of a NBC Filter comprising a tubular formation of an inner filter medium closed at at least one end by a metallic inner end cap, a tubular mass of graulated carbon surrounding said inner filter medium to from an outer filter medium, a tubular mesh enclosing said outer filter medium, a annular, resilient gasket surrounding said inner end cap and an outer end cap of metallic material having a peripheral skirt which, in use, surrounds one end of the mesh tube while the gasket is compressed between the outer end cap and the carbon mass, the method comprising interposing a thixotropic adhesive between the inner periphery of the gasket and the inner end cap, between the outer periphery of the gasket and the mesh tube and between the gasket and the outer end cap.
Preferably a continuous bead of said adhesive is applied to the gasket while the latter is in an unstressed condition and where the latter projects from the mesh tube before the outer end cap is brought to compress the gasket with its skirt surrounding and riveted to the mesh tube.
The adhesive used is preferably MIL-A-46146B, Group II, Type 1, such as that known as “Loctite 5145”.
Preferably the outer surface of the inner end cap and the inner surface of the outer end cap are first sand-blasted and then cleaned prior to contact with the adhesive.
A preferred embodiment of the invention will now be described by way of example with reference to the accompanying Drawing,
FIG. 1, which is an exploded sectional elevation of a NBC filter.
The NBC filter 10 illustrated comprises a tubular formation 11 of pleated cellulose paper impregnated and/or coated with microfibre glass. This is surrounded in spaced relation by a perforated metal housing or mesh tube 12 backed by a fine fabric scrim (not shown). The annular space between the mesh 12 and inner filter medium 11 is filled with a loose mass of granulated carbon (not shown). At one end of the filter (the lower as shown) a socket 13 permits the admission to the interior of the tube 11 of air rom outside the enclosure from, cabin or the like) being protected by the filter. A lower end cap 14 surrounds socket 13 and closes off the bottom end of the formation 11 and the lower end of the space between it and the housing 12.
At the upper end of the filter a metallic, inner end cap is closes the top end of the formation 11. An annular gasket 16 of resilient material, such as Neoprene rubber, is located on the tubular mass of carbon granules so that in its unstressed condition it projects slightly fromthe tubes 11 and 12. The gasket 16 is compressed when an outer end cap 17 of a metallic material is now brought down until its peripheral skirt 18 surrounds the upper end of the housing 12. Rivets (not shown) may now be used to secure the skirt 18 of the outer end cap to the housing 12.
As so far described the filter is known. In accordance with the present invention, however, prior to compression of the gasket 16 by the outer end cap 17 a continuous bead of a thixotropic adhesive is applied to a surface of the gasket 16 exposed from the carbon granules, for example a peripheral region of its upper surface as show so that when the outer end cap 17 is brought to compress the gasket there will be adhesive between the outer periphery 19 of the gasket and both the inner surface of the skirt 18 of the outer end cap and the outer surface of the metal mesh 12.
Preferably there is also adhesive between the inner periphery of the gasket 16 and the outer surface of the inner end cap 15.
Prior to assembly of the filter 10 the outer surface of the inner end cap 15 and the inner surface of the outer end cap 17 have been first sand-blasted and then cleaned to promote bond with the adhesive. The adhesive used is preferably MIL-A-46146B, Group II, Type 1, such as that known as “Loctite 5145”.
During assembly and before the adhesive cures the latter will serve as a lubricant and it will fill any voids between the mesh the gasket and the outer end cap. After cure the adhesive will provide a seal against the escape of carbon powder but will retain sufficient resilience to allow the gasket to unction as in prior art filters.
Claims (3)
1. A method of assembly of a NBC filter comprising a tubular formation of an inner filter medium closed at at least one end by a metallic inner end cap having a first peripheral skirt, a tubular mass of granulated carbon surrounding said inner filter medium to form an outer filter medium, a mesh tube enclosing said outer filter medium, an annular, resilient gasket surrounding said inner end cap and an outer end cap of metallic material having a second peripheral skirt which, in use, surrounds one end of the mesh tube while the gasket is compressed between the outer end cap and the carbon mass,
the method comprising interposing a thixotropic adhesive between the inner periphery of the gasket and the first peripheral skirt of the inner end cap, between the outer periphery of the gasket and mesh tube and between the gasket and the outer end cap, and allowing said adhesive to cure,
wherein during assembly and before said adhesive cures said adhesive fills any voids between said mesh tube, said gasket and said outer end cap, and after curing said adhesive provides a seal against escape of particulate matter from said carbon mass but retains sufficient resilience to allow said gasket to function,
and wherein said adhesive does not bond said inner filter medium to said inner end cap.
2. A method according to claim 1 wherein a continuous bead of said adhesive is applied to the gasket while the latter is in an unstressed condition and where the latter projects from the mesh tube before the outer end cap is brought to compress the gasket with its skirt surrounding and riveted to the mesh tube.
3. A method according to claim 1 wherein the outer surface of the inner end cap and the inner surface of the outer end cap are first sand-blasted and the cleaned prior to contact with the adhesive.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| GB9800831A GB2333248B (en) | 1998-01-16 | 1998-01-16 | The use of a thixotropic adhesive for the seal of a NBC filter |
| GB9800831 | 1998-01-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US6340402B1 true US6340402B1 (en) | 2002-01-22 |
Family
ID=10825336
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US09/232,563 Expired - Fee Related US6340402B1 (en) | 1998-01-16 | 1999-01-15 | Filters |
Country Status (2)
| Country | Link |
|---|---|
| US (1) | US6340402B1 (en) |
| GB (1) | GB2333248B (en) |
Cited By (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040251190A1 (en) * | 2003-04-04 | 2004-12-16 | The Clorox Company | Microorganism-removing filter medium having high isoelectric material and low melt index binder |
| US6989101B2 (en) | 2003-04-04 | 2006-01-24 | The Clorox Company | Microorganism-removing filter medium having high isoelectric material and low melt index binder |
| DE102009039281A1 (en) * | 2009-08-28 | 2011-03-03 | Mahle International Gmbh | Air cleaner, particularly for filtering fresh air supplied to vehicle interior, has channel shaped filter material folded in such manner that multiple folds are arranged next to each other |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US11060758B2 (en) * | 2016-02-26 | 2021-07-13 | 3M Innovative Properties Company | Air conditioner filter and method of manufacture |
| CN113117432A (en) * | 2021-04-15 | 2021-07-16 | 哈尔滨工程大学 | Fire-resistant and radiation-resistant metal fiber filter |
Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3528557A (en) | 1969-10-14 | 1970-09-15 | Marvel Eng Co | Filter construction |
| US3996409A (en) * | 1973-08-20 | 1976-12-07 | Ppg Industries, Inc. | High temperature adhesive-sealant composition |
| GB1570385A (en) | 1975-11-15 | 1980-07-02 | Crosland Filters Ltd | Filter |
| US4533422A (en) * | 1983-08-31 | 1985-08-06 | Loctite Corporation | Thixotropic cyanoacrylate compositions |
| US4725323A (en) | 1985-05-22 | 1988-02-16 | Cuno Incorporated | Filter element |
| US5580456A (en) * | 1993-12-16 | 1996-12-03 | W. L. Gore & Associates, Inc. | Filter cap affixed to a filter sleeve |
| US5711878A (en) * | 1995-11-02 | 1998-01-27 | Chisso Corporation | Cylindrical filter |
| US5714030A (en) * | 1992-12-07 | 1998-02-03 | Tsuchiya Mfg. Co., Ltd. | Plastisol type adhesive composition used in filter for alcohol-containing fuel |
-
1998
- 1998-01-16 GB GB9800831A patent/GB2333248B/en not_active Expired - Fee Related
-
1999
- 1999-01-15 US US09/232,563 patent/US6340402B1/en not_active Expired - Fee Related
Patent Citations (8)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3528557A (en) | 1969-10-14 | 1970-09-15 | Marvel Eng Co | Filter construction |
| US3996409A (en) * | 1973-08-20 | 1976-12-07 | Ppg Industries, Inc. | High temperature adhesive-sealant composition |
| GB1570385A (en) | 1975-11-15 | 1980-07-02 | Crosland Filters Ltd | Filter |
| US4533422A (en) * | 1983-08-31 | 1985-08-06 | Loctite Corporation | Thixotropic cyanoacrylate compositions |
| US4725323A (en) | 1985-05-22 | 1988-02-16 | Cuno Incorporated | Filter element |
| US5714030A (en) * | 1992-12-07 | 1998-02-03 | Tsuchiya Mfg. Co., Ltd. | Plastisol type adhesive composition used in filter for alcohol-containing fuel |
| US5580456A (en) * | 1993-12-16 | 1996-12-03 | W. L. Gore & Associates, Inc. | Filter cap affixed to a filter sleeve |
| US5711878A (en) * | 1995-11-02 | 1998-01-27 | Chisso Corporation | Cylindrical filter |
Cited By (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US20040251190A1 (en) * | 2003-04-04 | 2004-12-16 | The Clorox Company | Microorganism-removing filter medium having high isoelectric material and low melt index binder |
| US6989101B2 (en) | 2003-04-04 | 2006-01-24 | The Clorox Company | Microorganism-removing filter medium having high isoelectric material and low melt index binder |
| US7303683B2 (en) | 2003-04-04 | 2007-12-04 | The Clorox Company | Microorganism-removing filter medium having high isoelectric material and low melt index binder |
| DE102009039281A1 (en) * | 2009-08-28 | 2011-03-03 | Mahle International Gmbh | Air cleaner, particularly for filtering fresh air supplied to vehicle interior, has channel shaped filter material folded in such manner that multiple folds are arranged next to each other |
Also Published As
| Publication number | Publication date |
|---|---|
| GB9800831D0 (en) | 1998-03-11 |
| GB2333248A (en) | 1999-07-21 |
| GB2333248B (en) | 2002-03-20 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| AS | Assignment |
Owner name: MICROTECH FILTERS LIMITED, ENGLAND Free format text: ASSIGNMENT OF ASSIGNORS INTEREST;ASSIGNOR:HALPIN, BRETT;REEL/FRAME:010225/0425 Effective date: 19990909 |
|
| REMI | Maintenance fee reminder mailed | ||
| LAPS | Lapse for failure to pay maintenance fees | ||
| STCH | Information on status: patent discontinuation |
Free format text: PATENT EXPIRED DUE TO NONPAYMENT OF MAINTENANCE FEES UNDER 37 CFR 1.362 |
|
| FP | Lapsed due to failure to pay maintenance fee |
Effective date: 20060122 |